The present invention relates to a method of identifying a substance altering glucose uptake and/or GLUT4 translocation to the plasma membrane of a cell comprising contacting a test system comprising AKT substrate 160 kDa-protein (AS160-protein) with a test substance, and identifying a test substance as a substance altering glucose uptake of a cell by detecting a signal indicative for altered glucose uptake of a cell; a test system comprising a gene coding for the AKT substrate 160 kDa-protein (AS160-protein) and an inducible promoter providing for controllable expression of the gene; the use of the test system for the identification of a substance improving glucose uptake and/or GLUT4 translocation to the plasma membrane of a cell; and the use of AS 160-protein in a model for type 2 diabetes.